Immunomodulatory therapy for pediatric inflammatory bowel disease: changing patterns of use, 1990-2000

Toxoplasma ROP16I/III ameliorated inflammatory bowel diseases via inducing M2 phenotype of macrophages

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by chronic and non-specific inflammation of the intestinal mucosa and mainly includes ulcerative colitis and Crohn's disease.

AIM

To explore the beneficial effect of ToxoROP16_I/III-induced M2 phynotype macrophages in homeostasis of IBDs through downregulation of M1 inflammatory cells.

METHODS

RAW264.7 macrophages stimulated by lipopolysaccharide (LPS) (M1 cells) were co-cultured with Caco-2 cells as an inflammatory model of IBD in vitro. The expression of ToxoROP16_I/III was observed in RAW264.7 macrophages that were transfected with pEGFP-rop16_I/III. The phenotypes of M2 and M1 macrophage cells were assessed by quantitative real-time reverse transcriptase polymerase chain reaction and the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, transforming growth factor (TGF)-β1, IL-10, inducible nitric oxide synthase (iNOS), and arginase-1 (Arg-1) was detected. The expression of iNOS, Arg-1, signal transducer and activator of transcription 3 (Stat3), p-Stat3, Stat6, p-Stat6, programmed death ligand-2 (PD-L2), caspase-3, -8, and -9 was analyzed by Western blotting, and Griess assays were performed to detect nitric oxide (NO). TNF-α, IL-1β, IL-6, TGF-β1, and IL-10 expression in the supernatants was detected by enzyme-linked immunosorbent assay, and Caco-2 cell apoptosis was determined by flow cytometry after mixing M1 cells with M2 cells in a Caco-2 cell co-culture system.

RESULTS

M1 cells exhibited significantly increased production of iNOS, NO, TNF-α, IL-1β, and IL-6, while ToxoROP16_I/III induced macrophage bias to M2 cells in vitro, showing increased expression of Arg-1, IL-10 and TGF-β1 and elevated production of p-Stat3 and p-Stat6. The mixed M1 and M2 cell culture induced by ToxoROP16_I/III exhibited decreased production of NO and iNOS and upregulated expression of Arg-1 and PD-L2. Accordingly, Caco-2 cells became apoptotic, and apoptosis-associated proteins such as caspase-3, -8 and -9 were dampened during co-culture of M1 and M2 cells. Flow cytometry analysis showed that co-culture of M1 cells with Caco-2 cells facilitated the apoptosis of Caco-2 cells, but co-culture of M1 and M2 cells alleviated Caco-2 cell apoptosis.

CONCLUSION

ToxoROP16_I/III-induced M2 macrophages inhibited apoptosis of Caco-2 cells caused by M1 macrophages. This finding may help gain a better understanding of the underlying mechanism and represent a promising therapeutic strategy for IBDs.

Role of autophagy in the pathogenesis of inflammatory bowel disease

Inflammatory bowel disease (IBD) results from a complex series of interactions between susceptibility genes, the environment, and the immune system. Recently, some studies provided strong evidence that the process of autophagy affects several aspects of mucosal immune responses. Autophagy is a cellular stress response that plays key roles in physiological processes, such as innate and adaptive immunity, adaptation to starvation, degradation of aberrant proteins or organelles, antimicrobial defense, and protein secretion. Dysfunctional autophagy is recognized as a contributing factor in many chronic inflammatory diseases, including IBD. Autophagy plays multiple roles in IBD pathogenesis by altering processes that include intracellular bacterial killing, antimicrobial peptide secretion by Paneth cells, goblet cell function, proinflammatory cytokine production by macrophages, antigen presentation by dendritic cells, and the endoplasmic reticulum stress response in enterocytes. Recent studies have identified susceptibility genes involved in autophagy, such as NOD2, ATG16L1, and IRGM, and active research is ongoing all over the world. The aim of this review is a systematic appraisal of the current literature to provide a better understanding of the role of autophagy in the pathogenesis of IBD. Understanding these mechanisms will bring about new strategies for the treatment and prevention of IBD.

Suspected azathioprine induced liver cirrhosis: an unusual side effect

In recent years, the hepatotoxic potential of thiopurines, in particular 6-thioguanine (6-TG) has been discussed in literature. However, cirrhosis was exceptionally reported. We report the case of a 56-year-old woman with ileocaecal Crohn's disease treated with azathioprine. After taking azathioprine (2 mg/kg daily) for four years, she underwent surgical treatment for acute intestinal obstruction. In peroperative, we noticed a cirrhotic liver. A surgical biopsy was performed and the diagnosis of cirrhosis was confirmed. Autoimmune and viral liver diseases were ruled out by laboratory parameters. Therefore, Azathioprine is believed to be the causative actor for inducing liver cirrhosis. Thus, treating inflammatory bowel disease effectively while trying to limit iatrogenic disease is a continuous struggle.

Trends in early outpatient drug therapy in pediatric inflammatory bowel disease in Finland: a nationwide register-based study in 1999-2009

Objective. There are limited data on the changes of treatment strategies of disease-modifying drugs used to treat pediatric inflammatory bowel disease (IBD). Methods. We utilized data from two national registers: the Drug Reimbursement Register for drug costs (for identifying children with IBD) and the Drug Purchase Register (for exposure to drugs), both of which are maintained by the Social Insurance Institution of Finland. The frequencies and trends of drug therapy strategies during the first year of pediatric IBD were evaluated between 1999 and 2009. Results. A total of 481 children diagnosed with IBD were identified. During the first six months, 68% of the patients purchased systemic corticosteroids; these combined with 5-aminosalicylic acid in almost all cases. The use of corticosteroids was stable from the early years compared with the end of the study period. In Crohn's disease, there was a trend towards more active use of azathioprine: the therapy was introduced earlier and proportion of pediatric patients purchasing azathioprine increased by up to 51% (P < 0.05). Conclusions. In pediatric IBD, the majority of patients purchased corticosteroid within the first six months, reflecting moderate-to-severe disease. During recent years in pediatric Crohn's disease, the therapeutic strategies of oral medication have changed towards more active immunosuppression with azathioprine.

Association of Crohn's disease, thiopurines, and primary epstein-barr virus infection with hemophagocytic lymphohistiocytosis

OBJECTIVE

To assess the incidence of hemophagocytic lymphohistiocytosis (HLH) in a well-defined population of children with inflammatory bowel disease (IBD) and evaluate the common clinical and laboratory characteristics of individuals with IBD who developed HLH.

STUDY DESIGN

We conducted a retrospective study of all children who developed HLH over an 8-year period. The incidence of HLH in patients with IBD was calculated using US census data and a statewide project examining the epidemiology of pediatric IBD.

RESULTS

Among children in Wisconsin, 20 cases of HLH occurred during the study period; 5 cases occurred in children with IBD. Common characteristics include: Crohn's disease (CD), thiopurine administration, fever lasting more than 5 days, lymphadenopathy, splenomegaly, anemia, lymphopenia, and elevated serum triglycerides and ferritin. Of the patients, 4 had primary Epstein-Barr virus infections. The incidence of HLH among all children in Wisconsin was 1.5 per 100 000 per year. The risk was more than 100-fold greater for children with CD (P < .00001).

CONCLUSIONS

Pediatric patients with CD are at increased risk for developing HLH; primary Epstein-Barr virus infection and thiopurine administration may be risk factors.

Cystic fibrosis and Crohn’s disease: Successful treatment and long term remission with infliximab

The association of cystic fibrosis and Crohn’s disease (CD) is well known, but to date, there are very few cases in the literature of patients suffering from mucoviscidosis who have required treatment with infliximab. We report the case of a 23-year-old patient suffering from cystic fibrosis and severe CD treated successfully with infliximab without any infective complications or worsening of the pulmonary disease and with a long term (2 years) complete remission.

IBD in children: lessons for adults

When children develop inflammatory bowel disease (IBD), physicians and researchers are presented with a singular opportunity to understand the nature of these chronic, idiopathic illnesses in the earliest stages. Genetic susceptibility factors tend to be common, whereas complicating environmental factors such as cigarette smoking are generally not an issue. As opposed to the case in adult patients, Crohn's disease is usually diagnosed in children at an early, inflammatory phase of the disease. Pediatric ulcerative colitis tends to present with more severe and more extensive involvement than in adults. In both forms of IBD, the severity of disease activity often dictates the need for early aggressive nutritional, immunomodulatory, and biologic therapy. As a result, the lessons learned from the evaluation and treatment of children with IBD are critically important to the clinician caring for adults with the same disorders.

Current therapy of inflammatory bowel disease in children

Ulcerative colitis (UC) and Crohn disease (CD) are chronic intestinal inflammatory diseases that can present as bloody diarrhea, abdominal pain, and malnutrition. Collectively, these disorders are referred to as inflammatory bowel disease (IBD). All patients with IBD share a common pathophysiology. However, there are a number of developmental, psychosocial, and physiologic issues that are unique to the approximate, equals 20% of patients that present during childhood or adolescence. These include the possibility of disease-induced delays in linear growth or physical development, differences in drug dosing, and the changes in social and cognitive development that occur as children move from school-age years into adolescence and early adulthood. Gastroenterologists caring for these children must therefore develop an optimal regimen of pharmacologic therapies, nutritional management, psychologic support, and properly timed surgery (when necessary) that will maintain disease remission, minimize disease and drug-induced adverse effects, and optimize growth and development. This article reviews current approaches to the management of patients with UC and CD and highlights issues specific to the treatment of children with IBD. The principal medical therapies used to induce disease remission in patients with UC are aminosalicylates (for mild disease), corticosteroids (for moderate disease), and cyclosporine (ciclosporin) (for severe disease). If a patient responds to the induction regimen, maintenance therapies that are used to prevent disease relapse include aminosalicylates, mercaptopurine, and azathioprine. Colectomy with creation of an ileal pouch anal anastomosis (J pouch) has become the standard of care for patients with severe or refractory colitis and results in an improved quality of life in most patients. Therefore, the risks associated with using increasingly potent immunosuppressant agents must be balanced in each case against a patient's desire to retain their colon and avoid a temporary or potentially permanent ileostomy. Decisions about drug therapy in the management of patients with CD are more complex and depend on both the location (e.g. gastroduodenal vs small intestinal vs colonic), as well as the behavior of the disease (inflammatory/mucosal vs stricturing vs perforating) in a given patient. Induction therapies for CD typically include aminosalicylates and antibiotics (for mild mucosal disease), nutritional therapy (including elemental or polymeric formulas), corticosteroids (for moderate disease), and infliximab (for corticosteroid-resistant or fistulizing disease). Aminosalicylates, mercaptopurine, azathioprine, methotrexate, and infliximab can be used as maintenance therapies. Because surgical treatment of CD is not curative, it is typically reserved for those patients either with persistent symptoms and disease limited to a small section of the intestine (e.g. the terminal ileum and cecum) or for the management of complications of the disease including stricture or abdominal abscess. When surgery is necessary, maintenance medications administered postoperatively will postpone recurrence. Patients with UC and CD are at risk for the development of micronutrient deficiencies (including folate, iron, and vitamin D deficiencies) and require close nutritional monitoring. In addition, patients with UC and CD involving the colon are at increased risk of developing colon cancer, and should be enrolled into a colonoscopy surveillance program after 8-10 years of disease duration.

Pediatric inflammatory bowel disease

Inflammatory bowel disease is an important cause of gastrointestinal pathology in children and adolescents. The incidence of pediatric inflammatory bowel disease is increasing; therefore, it is important for the clinician to be aware of the presentation of this disease in the pediatric population. Laboratory tests, radiology studies, and endoscopic procedures are helpful in diagnosing inflammatory bowel disease and differentiating between Crohn’s disease and ulcerative colitis. Once diagnosed, the goal of medical management is to induce remission of disease while minimizing the side effects of the medication. Specific attention needs to be paid to achieving normal growth in this susceptible population. Surgical management is usually indicated for failure of medical management, complication, or malignancy. Algorithms for diagnostic evaluation and treatment of pediatric inflammatory bowel disease are presented. The specific psychosocial issues facing these patients are also discussed in this review as are the future goals of research in the complex problem of pediatric inflammatory bowel disease.

New patients: should children be treated differently?

Inflammatory bowel disease (IBD) in childhood is often diagnosed at a vulnerable time of growth and development, and is recognized as one of the most significant chronic gastrointestinal diseases to affect children. Children and adolescents with IBD are at increased risk of complications as a result of malnutrition secondary to reduced appetite, increased metabolism and decreased absorptive capacity. The most common and serious complications are growth failure, bone demineralization and impaired psychosocial development. These issues add to the complexity of childhood IBD management and it is essential that adequate medical management is in place to prevent these long-term complications. Current treatment options include 5-aminosalicylic acid, antibiotics, corticosteroids, nutritional therapy and immunomodulators used to induce and maintain remission; some are specifically employed to maintain a steroid free long-term remission. As a general rule, long-term corticosteroid use should be avoided to reduce the risk of bone demineralization and growth failure. Newer treatment options such as infliximab have been shown to be effective for inducing and prolonging remission of Crohn's disease in children and paediatric use of infliximab is likely to increase in the near future. A recent case report, involving a 15-year old boy presenting with abdominal pain and bloody diarrhoea, illustrates the difficulty in correctly diagnosing IBD in children and the need for optimizing therapy to achieve treatment success.

Usefulness of omega-3 fatty acid supplementation in addition to mesalazine in maintaining remission in pediatric Crohn's disease: a double-blind, randomized, placebo-controlled study

AIM

To assess the value of long-chain omega-3 fatty acids (FAs) supplementation in addition to amino-salicylic-acid (5-ASA) in pediatric patients with Crohn's disease (CD).

METHODS

Thirty-eight patients (20 males and 18 females, mean age 10.13 years, range 5-16 years) with CD in remission were randomized into two groups and treated for 12 mo. Group I (18 patients) received 5-ASA (50 mg/kg/d)+ omega-3 FAs as triglycerides in gastro-resistant capsules, 3 g/d (eicosapentanoic acid, EPA, 400 mg/g, docosahexaenoic acid, DHA, 200 mg/g). Group II (20 patients) received 5-ASA (50 mg/kg/d)+olive oil placebo capsules. Patients were evaluated for fatty acid incorporation in red blood cell membranes by gas chromatography at baseline 6 and 12 mo after the treatment.

RESULTS

The number of patients who relapsed at 1 year was significantly lower in group I than in group II (P<0.001). Patients in group I had a significant increase in the incorporation of EPA and DHA (P<0.001) and a decrease in the presence of arachidonic acids.

CONCLUSION

Enteric-coated omega-3 FAs in addition to treatment with 5-ASA are effective in maintaining remission of pediatric CD.

Crohn's disease presenting as palatal ulcer

Crohn's disease (CD) in children younger than 5 years of age is termed as early onset inflammatory bowel disease (EO-IBD). We report a 4 yr 6 mo-old child with EO-IBD, who presented with palatal ulcer, an extra intestinal manifestation of Crohn's disease as the dominant feature.

Incidence, risk factors and clinical course of thiopurine-induced liver injury in patients with inflammatory bowel disease

BACKGROUND

The incidence of thiopurine-induced hepatotoxicity in patients with inflammatory bowel disease varies in different studies.

AIMS

To assess the rate of thiopurine-induced liver toxicity in patients with inflammatory bowel disease; to determine the predictive factors and to characterize its clinical course and management.

METHODS

A cohort of 161 patients was prospectively followed for a median of 271 days. Hepatotoxicity was established when alanine transaminase or alkaline phosphatase plasma levels were greater than twice the upper normal limit.

RESULTS

Abnormal liver function was detected in 21 patients (13%; 95% CI: 7-18). Hepatotoxicity occurred in 16 patients (10%; 95% CI: 6-16) after a median of 85 days. In five cases, treatment was withdrawn due to hepatotoxicity. Use of corticosteroids was associated with hepatotoxicity (OR: 4.94; 95% CI: 1.01-23.98) with antitumour necrosis factor concomitant therapy showing a protective role (OR: 0.3; 95% CI: 0.1-3.1). gamma-Glutamyl transferase plasma levels at the onset of hepatotoxicity showed the best predictive value for treatment withdrawal (area under the receiver operating characteristic curve: 0.95).

CONCLUSIONS

The incidence of hepatotoxicity in inflammatory bowel disease patients receiving thiopurines is relevant, mainly in patients co-treated with corticosteroids. gamma-Glutamyl transferase plasma level is a useful biomarker in therapy withdrawal prediction.

A national survey on the patterns of treatment of inflammatory bowel disease in Canada

BACKGROUND

There is a general lack of information on the care of inflammatory bowel disease (IBD) in a broad, geographically diverse, non-clinic population. The purposes of this study were (1) to compare a sample drawn from the membership of a national Crohn's and Colitis Foundation to published clinic-based and population-based IBD samples, (2) to describe current patterns of health care use, and (3) to determine if unexpected variations exist in how and by whom IBD is treated.

METHODS

Mailed survey of 4453 members of the Crohn's and Colitis Foundation of Canada. The questionnaire, in members stated language of preference, included items on demographic and disease characteristics, general health behaviors and current and past IBD treatment. Each member received an initial and one reminder mailing.

RESULTS

Questionnaires were returned by 1787, 913, and 128 people with Crohn's disease, ulcerative colitis and indeterminate colitis, respectively. At least one operation had been performed on 1159 Crohn's disease patients, with risk increasing with duration of disease. Regional variation in surgical rates in ulcerative colitis patients was identified. 6-mercaptopurine/azathioprine was used by 24% of patients with Crohn's disease and 12% of patients with ulcerative colitis (95% CI for the difference: 8.9%-15%). In patients with Crohn's disease, use was not associated with gender, income or region of residence but was associated with age and markers of disease activity. Infliximab was used by 112 respondents (4%), the majority of whom had Crohn's disease. Variations in infliximab use based on region of residence and income were not seen. Sixty-eight percent of respondents indicated that they depended most on a gastroenterologist for their IBD care. There was significant regional variation in this. However, satisfaction with primary physician did not depend on physician type (for example, gastroenterologist versus general practitioner).

CONCLUSION

This study achieved the goal of obtaining a large, geographically diverse sample that is more representative of the general IBD population than a clinic sample would have been. We could find no evidence of significant regional variation in medical treatments due to gender, region of residence or income level. Differences were noted between different age groups, which deserves further attention.